diff --git a/Tests/MeshLib/TestIs2DMeshOnRotatedVerticalPlane.cpp b/Tests/MeshLib/TestIs2DMeshOnRotatedVerticalPlane.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6fdb704bbad1078f4845a7d1008b1858fb11adf9
--- /dev/null
+++ b/Tests/MeshLib/TestIs2DMeshOnRotatedVerticalPlane.cpp
@@ -0,0 +1,187 @@
+/**
+ * \file
+ * \copyright
+ * Copyright (c) 2012-2021, OpenGeoSys Community (http://www.opengeosys.org)
+ * Distributed under a Modified BSD License.
+ * See accompanying file LICENSE.txt or
+ * http://www.opengeosys.org/project/license
+ *
+ * Created on May 10, 2021, 3:09 PM
+ */
+
+#include <gtest/gtest.h>
+
+#include <array>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "MeshLib/Elements/Element.h"
+#include "MeshLib/Elements/Elements.h"
+#include "MeshLib/Mesh.h"
+#include "MeshLib/MeshEnums.h"
+#include "MeshLib/Node.h"
+#include "MeshLib/Utils/Is2DMeshOnRotatedVerticalPlane.h"
+#include "MeshLib/Utils/SetMeshSpaceDimension.h"
+template <typename ElementType, int NodeNumber>
+void testAsNoVerticalPlaneMesh(
+ std::string const& error_message,
+ const unsigned expected_space_dimension,
+ std::array<MeshLib::Node*, NodeNumber> const& element_nodes)
+{
+ std::vector<MeshLib::Element*> elements{new ElementType(element_nodes)};
+
+ std::vector<MeshLib::Node*> nodes(element_nodes.begin(),
+ element_nodes.end());
+
+ std::vector<std::unique_ptr<MeshLib::Mesh>> meshes;
+ meshes.push_back(
+ std::make_unique<MeshLib::Mesh>("a_mesh", nodes, elements));
+
+ MeshLib::setMeshSpaceDimension(meshes);
+ ASSERT_EQ(expected_space_dimension, elements[0]->space_dimension_);
+
+ try
+ {
+ MeshLib::is2DMeshOnRotatedVerticalPlane(*meshes[0]);
+ }
+ catch (std::exception& e)
+ {
+ EXPECT_EQ(e.what(), error_message);
+ }
+}
+
+void testAsVerticalPlaneMesh(const unsigned expected_space_dimension,
+ std::array<MeshLib::Node*, 4> const& element_nodes)
+{
+ std::vector<MeshLib::Element*> elements{new MeshLib::Quad(element_nodes)};
+
+ std::vector<MeshLib::Node*> nodes(element_nodes.begin(),
+ element_nodes.end());
+
+ std::vector<std::unique_ptr<MeshLib::Mesh>> meshes;
+ meshes.push_back(
+ std::make_unique<MeshLib::Mesh>("a_mesh", nodes, elements));
+
+ MeshLib::setMeshSpaceDimension(meshes);
+
+ if (expected_space_dimension == 3u)
+ {
+ ASSERT_EQ(3u, elements[0]->space_dimension_);
+
+ ASSERT_TRUE(MeshLib::is2DMeshOnRotatedVerticalPlane(*meshes[0]));
+ }
+ else
+ {
+ ASSERT_EQ(2u, elements[0]->space_dimension_);
+
+ ASSERT_FALSE(MeshLib::is2DMeshOnRotatedVerticalPlane(*meshes[0]));
+ }
+}
+
+TEST(MeshLib, Is2DMeshOnRotatedVerticalPlane)
+{
+ // The memory of the nodes are allocated by new operator, and it is released
+ // in the destructor of MeshLib::Mesh.
+
+ // 3D mesh:
+ {
+ std::array<MeshLib::Node*, 4> element_nodes;
+ element_nodes[0] = new MeshLib::Node(0.0, 0.0, 0.0, 0);
+ element_nodes[1] = new MeshLib::Node(1.0, 0.0, 0.0, 1);
+ element_nodes[2] = new MeshLib::Node(0.0, 1.0, 0.0, 2);
+ element_nodes[3] = new MeshLib::Node(0.0, 0.0, 1.0, 3);
+
+ std::string const error_message =
+ "A 2D mesh is required for this "
+ "computation but the provided mesh, "
+ "mesh a_mesh, has 3D elements.";
+
+ auto const expected_space_dimension = 3u;
+ testAsNoVerticalPlaneMesh<MeshLib::Tet, 4>(
+ error_message, expected_space_dimension, element_nodes);
+ }
+
+ // Inclined 2D mesh but it is not on a plane rotated around the vertical
+ // axis:
+ {
+ std::array<MeshLib::Node*, 4> element_nodes;
+ element_nodes[0] = new MeshLib::Node(0.0, 0.0, 0.0, 0);
+ element_nodes[1] = new MeshLib::Node(1.0, 1.0, 0.0, 1);
+ element_nodes[2] = new MeshLib::Node(0.2, 0.5, 1.0, 2);
+ element_nodes[3] = new MeshLib::Node(1.2, 1.5, 0.0, 3);
+
+ std::string const error_message =
+ "2D Mesh a_mesh is on an inclined plane, which is neither a "
+ "vertical nor horizontal plane that is required for the present "
+ "computation.";
+
+ auto const expected_space_dimension = 3u;
+ testAsNoVerticalPlaneMesh<MeshLib::Quad, 4>(
+ error_message, expected_space_dimension, element_nodes);
+ }
+
+ // 1D mesh:
+ {
+ std::array<MeshLib::Node*, 2> element_nodes;
+ element_nodes[0] = new MeshLib::Node(0.0, 0.0, 0.0, 0);
+ element_nodes[1] = new MeshLib::Node(0.2, 0.5, 1.0, 1);
+
+ std::string const error_message =
+ "A 2D mesh is required for this "
+ "computation but the provided mesh, "
+ "mesh a_mesh, has 1D elements.";
+
+ auto const expected_space_dimension = 3u;
+ testAsNoVerticalPlaneMesh<MeshLib::Line, 2>(
+ error_message, expected_space_dimension, element_nodes);
+ }
+
+ // 2D mesh on x-y plane:
+ {
+ std::array<MeshLib::Node*, 4> element_nodes;
+ element_nodes[0] = new MeshLib::Node(0.0, 0.0, 0.0, 0);
+ element_nodes[1] = new MeshLib::Node(1.0, 0.0, 0.0, 1);
+ element_nodes[2] = new MeshLib::Node(1.0, 1.0, 0.0, 2);
+ element_nodes[3] = new MeshLib::Node(0.0, 1.0, 0.0, 3);
+
+ auto const expected_space_dimension = 2u;
+ testAsVerticalPlaneMesh(expected_space_dimension, element_nodes);
+ }
+
+ // 2D mesh on x-z plane:
+ {
+ std::array<MeshLib::Node*, 4> element_nodes;
+ element_nodes[0] = new MeshLib::Node(0.0, 0.0, 0.0, 0);
+ element_nodes[1] = new MeshLib::Node(1.0, 0.0, 0.0, 1);
+ element_nodes[2] = new MeshLib::Node(1.0, 0.0, 1.0, 2);
+ element_nodes[3] = new MeshLib::Node(0.0, 0.0, 1.0, 3);
+
+ auto const expected_space_dimension = 2u;
+ testAsVerticalPlaneMesh(expected_space_dimension, element_nodes);
+ }
+
+ // 2D mesh on the plane rotated around y axis:
+ {
+ std::array<MeshLib::Node*, 4> element_nodes;
+ element_nodes[0] = new MeshLib::Node(0.0, 0.0, 0.0, 0);
+ element_nodes[1] = new MeshLib::Node(0.2, 0.0, 0.5, 1);
+ element_nodes[2] = new MeshLib::Node(0.2, 1.0, 0.5, 2);
+ element_nodes[3] = new MeshLib::Node(0.0, 1.0, 0.0, 3);
+
+ auto const expected_space_dimension = 3u;
+ testAsVerticalPlaneMesh(expected_space_dimension, element_nodes);
+ }
+
+ // 2D mesh on the plane rotated around z axis:
+ {
+ std::array<MeshLib::Node*, 4> element_nodes;
+ element_nodes[0] = new MeshLib::Node(0.0, 0.0, 0.0, 0);
+ element_nodes[1] = new MeshLib::Node(0.2, 0.5, 0.0, 1);
+ element_nodes[2] = new MeshLib::Node(0.2, 0.5, 1.0, 2);
+ element_nodes[3] = new MeshLib::Node(0.0, 0.0, 1.0, 3);
+
+ auto const expected_space_dimension = 3u;
+ testAsVerticalPlaneMesh(expected_space_dimension, element_nodes);
+ }
+}